Visit to the VDI congress - Castings and body components

The manufacture of structural components for cast-iron cars was highlighted in the 3rd edition of the "Casting Chassis and Bodywork Components 2018" conference held on 20 and 21 February in Esslingen, Germany, organized by VDI Wissensforum. It is considered one of the most important congresses on the subject in German speaking countries. Digitalization, Industry 4.0, weight reduction and electric mobility, were some of the covered topics.

E-Mobility

Diesel vehicle registrations continue to decline in Europe, from 46% in 2016 to 41% in 2017. This trend is in line with several forecasts pointing to a marked increase in the use of hybrid and electrical vehicles in the upcoming years. It is estimated that by 2025, about 24% of cars sold in Europe are hybrids or electric.

Of course, this trend has repercussions across the value chain of the automotive sector, not just in OEMs. The foundries will also feel the effects of this change.

Various components produced by foundry for internal combustion vehicles are not applicable to the electrical, such as engine blocks and heads, injection systems, clutches, oil pumps and turbochargers. Other components will face modifications such as gearboxes, transmission and suspension. On the other hand, new components such as electrical motor housing and battery housing will emerge, providing a new opportunity for foundries, especially for aluminium alloys.

As in any "revolution," there are opportunities for those who best adapt and position themselves towards the new reality.

Foundry positioning

Foundries are experts in various areas of automotive component development. For example, developing new alloys, designs and producing more efficiently.

Through these specialties, foundries today have the opportunity to assert themselves within the market, not only as a supplier, but as a partner in delivering solutions.

Development teams in foundries should seek closer contact with customers and work together as specialists to develop new solutions and thus move up in the value chain.

For this new positioning, foundries must be well aware of the automobile evolution as well as the OEMs’ needs, mainly in relation to the components weight reduction strategy.

Strategies for weight reduction (design and materials)

Components weight reduction is a requirement for OEMs to improve fuel consumption and consequently reduce emissions of polluting gases. These needs remain in electrical vehicles where battery life is still far from the needs of most consumers.

The most efficient way to reduce weight in automotive components is through the combined development of new alloys with higher strength and new designs.

For many years now, some of the components produced in ferrous alloys (steel and cast iron) have been replaced by "light" alloys. The most widely used light alloy is aluminium, which due to its lower density in relation to the ferrous alloys (about 1/3 of the density) allows a significant weight reduction. However, aluminium has less mechanical strength than ferrous alloys. This requires aluminium alloys in many of their applications to be modified to improve their mechanical performance.

As an example, in the case of the Audi A8, the body is composed of 58% of aluminium alloys, but simultaneously had a 24% increase in stiffness by improving the properties of the aluminium alloy and innovation in the component’s design.

But aluminium is not the only choice nowadays for light weight solutions. There is an increasing use of magnesium in the automotive industry in very specific applications, but there is a tendency for its wider use.

However, it is also possible to achieve significant weight reductions using ferrous alloys in components where high mechanical strength is required and for which light alloys are not an option. The development of high strength steel alloys, vermicular cast iron and new nodular cast iron alloys (ADI and SiboDur) also allow significant weight reductions and achieve performances that were not possible with other materials.

In addition to new materials and design, the foundry can also give a major contribution to the components process production.

Modernization of light alloys casting techniques

The optimization of the casting process is crucial for the development and production of new components, and only those who are unaware of the industry may think that foundry is an "old" and limited process.

These acquisition, management and action systems on the process are transversal and applicable to any foundry process.

In the case of a high-pressure die casting process for the production of aluminium parts, one of the foundries of the Volkswagen group developed an "intelligent die" that locally adjusts the cooling rate in different sections of the part, using temperature sensors and internal controlled cooling fluid injectors on the die. This way it is possible to control the heat transfer coefficient in different section of the die.

Still in relation to aluminium alloys, many foundries are working to eliminate the need to perform the heat treatment step, in order to reduce production costs. The main approaches are the development of alloys that allow obtaining the final mechanical properties, especially the elongation, after solidification of the pieces.

In the production of magnesium components, the greatest challenge lies in controlling the atmosphere inside the furnace to prevent corrosion of liquid magnesium. Also here the acquisition of data and artificial intelligence can help, according to a recent work done by the University of Kassel in Germany. The project aimed to create an atmosphere control system inside the furnace (composed of several gases) to stabilize the protection of magnesium from corrosion.

In conclusion, the automotive industry continues to grow, despite the challenges it faces and much of its success depends on what the foundry industry is able to deliver.

As a suggestion, foundries should:

- Modernize, through investment in R&D, the adoption of new process control and production techniques (Industry 4.0);

- Betting on the development of new alloys, whether ferrous alloys or light alloys, as long as they are aligned with the needs of the automotive sector;

- Develop new processes that are more efficient or that allow the production of hybrid castings.

The foundry industry has in the present and in the future, as it has had in the past, a very important role in industry.